The radiochemistry core provides the radiopharmaceuticals as requested by the projects to fulfill the goals of the research described in this application. The specific aims are to produce C-11 and F-18, and to use these radionuclides to prepared the radioactive precursors: [C-11]NH4CN, [C-11]CH3I, and [F-18]fluoride, and to make the radiopharmaceuticals 2-[C- 11]thymidine; -[C-11]glucose; [F-18]-2-fluorodeoxyglucose; [F- 18]fluoromisonidazole; and 16-alpha-[F-18]fluoroestradiol. Robot-assisted and remotely operated syntheses are used to make procedures more convenient and to make radiation exposure to the chemists as low as reasonably used to make procedures more convenient and to keep radiation exposure to the chemists as low as reasonably achievable. The radiochemists are responsible for assuring the radiochemical purity and pharmaceutical quality of all products for in vivo studies and for compliance with all regulations regarding radiation and pharmaceutical safety.